I have been programming for a bit and for 2D games and other applications I frequently make large images for the levels / the maps. Before I place these into the games I split the large images down into smaller equally sized squares, but I do this manually in 'the Gimp' and it takes ages sometimes! Is there some software which can do this much quicker for me, where I can select how I want the image split down etc? And for Mac as well?

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if it's going to be a combination of command line editing tool with some scripting language you can also use ffmpeg, although it's mainly developed to edit videos but it can also manipulate images perfectly.
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Ali.SOct 22 '11 at 20:51

+1 ImageMagick is a great choice for tasks like this. Also very powerful with scripts (that could even be integrated into the build process)
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bummzackOct 22 '11 at 21:46

It may be good, but I have no idea how to use Terminal, and cannot figure out what to do to even get Terminal to see the program, I have used the Mac Port install option. But now have no idea what else to do :(
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Paul ReedOct 22 '11 at 22:40

Fantastic got it working and it is exactly what I wanted!
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Paul ReedOct 22 '11 at 23:01

An image editing program I use all the time is PixelMator (app store link). It's not free, but it's very good and takes advantage of OS X. I don't think it has a tool for specifying a size and getting images dice automatically, but it does have a tool expressly for dicing up images manually. It's designed for dealing with web site graphics which are often broken up.

I initially used the Gimp for mac and found it awkward to work with compared to the PC version, so tried PixelMator but it isn't accurate enough and would have taken just as long to do if not longer as it would have in Gimp :)
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Paul ReedOct 24 '11 at 8:12